After drycleaning, mysterious, local color loss sometimes occurs. Testing shows that the dye and sizing in the fabric are not affected by drycleaning solvents or water. Instead, the dye and sizing are disturbed by the combined effects of liquid prespotters and cleaning while wet.
Extreme care must be exercised whenever silk is prespotted with moisture or subjected to wetside stain removal procedures. Usually, the dye and sizing used on these fabrics will only be affected by extended contact with moisture used in stain removal, especially if the area is left damp when drycleaned.
Exercising care, most stains should be removed locally on the spotting board. Minimize the amount of moisture used. After the stain has been removed and the chemicals flushed from the fabric, hang the garment aside to allow the remaining moisture in the fabric to completely dry. Once the fabric is dry, it can be re-cleaned without the risk of any local color loss.
Remember, wetside prespotting should only be performed on solid colors. This procedure is not recommended for use on multi-colored fabrics unless thorough colorfastness testing is first performed. To test, apply a small amount of the stain removal agent to an inconspicuous area and let stand for five minutes. If the color is affected, the agent should not be used. When used properly, stain removal techniques on silk can remove many stains without damaging the fabric or color.
For more information, see the following documents in DLI's Online Encyclopedia of Drycleaning:
Fabrics & Fashions No. 494: Stain Removal Procedures for Silk Fabrics
Fabrics & Fashions No. 536: Color Failure on Silk